What is anesthesia?
Anesthesia is used to put patients into an artificial sleep. For this purpose, the responsible specialist (anesthesiologist) uses various drugs and/or gas mixtures.
Anesthesia enables operations and certain examination procedures to be performed that would otherwise only be possible in extreme pain. There are different procedures, which differ, among other things, in the anesthetic side effects and areas of application.
Inhalation anesthesia
In inhalation anesthesia, the anesthesia is produced by inhaling gaseous drugs, for example sevoflurane, isoflurane or nitrous oxide. These so-called volatile anesthetics switch off consciousness on the one hand, but also reduce the sensation of pain.
Inhalation anesthesia is the oldest form of anesthesia and today is usually combined with other procedures. Inhalation anesthesia alone is occasionally used in children.
Total intravenous anesthesia (TIA)
Balanced anesthesia
Balanced anesthesia combines the two methods mentioned above. Thus, at the beginning of the anesthesia, the patient usually receives intravenous drugs, and during the operation he or she also breathes in anesthetic gases. This reduces many anesthetic side effects and the consumption of strong painkillers.
Further information: Local anesthesia
For some operations, it is sufficient if only the pain sensation in a certain area is switched off. For more information, see local anesthesia.
Further information: Spinal anesthesia
In a special form of local anesthesia, the anesthetic is injected into the spinal canal. You can read more about this in the text Spinal anesthesia.
Further information: Peridural anesthesia (PDA).
There is another possibility to switch off the pain sensation close to the spinal cord. Read all about it in the article Peridural Anesthesia.
When is anesthesia performed?
Operations
The most common reason for anesthesia is surgery. Many operations, for example on abdominal organs, are made possible in the first place. The reduced consciousness also reduces the patient’s stress and promotes recovery after the operation. Anesthesia also gives the surgeon the best possible working conditions because the patient does not move. This is very important, for example, during operations on the brain or blood vessels.
Examinations
Some examination procedures also require anesthesia. For example, during a bronchoscopy with a rigid tube through the trachea, the patient would experience severe pain and coughing if he or she were not anesthetized. However, even infants on whom an MRI has to be performed are often given anesthesia so that they can lie still. The images taken would otherwise be blurred and unusable.
Emergency Medicine
If a patient’s independent breathing is impeded, for example after a cardiac arrest, serious accident or allergic reaction, he or she must be artificially ventilated. On the one hand, anesthesia makes it easier to safely administer artificial respiration; on the other hand, it relieves the pain that even unconscious patients still feel.
What is done during anesthesia?
For anesthesia, the anesthesiologist uses gas-air mixtures as well as various drugs. These can be divided into three groups.
- Hypnotics (sleeping pills) primarily turn off consciousness. An example is propofol.
- Analgesics (painkillers) suppress the sensation of pain. For anesthesia, give strong analgesics from the opioid group.
- Muscle relaxants relax the muscles and immobilize the patient. Depending on the application, they do not have to be used for every anesthetic.
Anesthesia information
Before a planned anesthesia, the anesthesiologist informs the patient in a detailed conversation about the procedure planned for him. He also asks about any previous illnesses and inquires about any medications regularly taken. In this way, the doctor assesses the risk of anesthesia and selects appropriate medications. If the patient is very anxious and afraid of anesthesia, he also gives a sedative to help him relax.
Induction of anesthesia
Before the induction of anesthesia, the patient breathes pure oxygen for several minutes. This creates an oxygen reserve in the blood for later insertion of the breathing tube (intubation). At the same time, the doctor places a needle in a vein, for example in the patient’s hand, through which he can inject the medication. A strong painkiller is followed by a high-dose sleeping pill, causing the patient to lose consciousness within a few seconds and stop breathing on his own.
During longer operations, the patient is warmed with a fan heater because otherwise the body would cool down quickly. A monitoring monitor also continuously displays important vital functions such as blood pressure, pulse, heart activity and respiratory rate. This allows the anesthesiologist to quickly identify potential anesthesia complications.
Rapid Sequence Induction
A special form of anesthesia induction is called rapid sequence induction (RSI). Here, the anesthetic drugs are administered in rapid succession and no mask ventilation is required in the meantime. It is used primarily in patients who are not fasting, pregnant women and patients with certain gastrointestinal disorders, and prevents the stomach contents from flowing back into the trachea.
Continuation of anesthesia and induction of anesthesia
Following surgery, the patient is monitored in the recovery room. A physician is constantly available there to administer painkillers if necessary and to assess the patient’s vital functions.
What are the risks of anesthesia?
General anesthesia carries the risk of many side effects. Anesthetic medications can cause sudden drops in blood pressure or cardiac arrhythmias, among other things. The anesthesiologist then treats these with drugs that support the circulation. All of the drugs used can also cause severe allergic reactions.
Problems during ventilation
A possible complication is tooth damage, as the doctor inserts the tube into the trachea with a special instrument (laryngoscope). Dentures are therefore removed before the operation. The tube itself can also cause damage to the vocal folds (vocal cords).
Malignant hyperthermia
Malignant hyperthermia is a dreaded muscle disorder that can occur very suddenly during anesthesia. In this case, the entire musculature tenses permanently, causing the body to heat up in a life-threatening manner. In addition to genetic factors and certain anesthetic gases, the muscle relaxant succinylcholine in particular is considered a possible trigger.
In contrast to the anesthetic gases, pure intravenous anesthesia is not a trigger for malignant hyperthermia, which is why it is also called trigger-free anesthesia.
Waking states during anesthesia
Anesthetic side effects
Anesthesia side effects can still occur after surgery. These include:
- Vomiting and nausea after anesthesia (postoperative nausea and vomiting = PONV).
- Shivering due to hypothermia
- Confusion
Vomiting and nausea in particular are common after-effects. Anesthetic medications, especially anesthetic gases, and a long duration of surgery are among the risk factors. However, by giving certain medications even before anesthesia, subsequent nausea can often be prevented.
Positional damage
What do I need to be aware of after anesthesia?
It is normal if you still feel a little confused and sleepy after anesthesia. However, if you feel pain, nausea, or discomfort in your arms, or if you are hoarse for a long time, you should tell the doctor. In consultation with the doctor, you may also take a few sips of water again. The exact time depends on the type of procedure.
If you have developed malignant hyperthermia during the anesthesia, the anesthesiologist will issue you with an emergency card. You must carry this with you at all times so that the anesthesiologists can select the correct anesthesia for you if you need surgery later.
